Connection control method for personal communications

ABSTRACT

A switching center 30 comprises a memory part M2, a memory part M3, and a memory part M4. The memory part M2 stores a terminating terminal number corresponding to and registered by each subscriber. The memory part M3 stores idle/busy information corresponding to each terminal. The memory part M4 stores idle/busy information corresponding to each subscriber. When a subscriber 11 1  makes a call at a terminal 12 2 , the switching center 30 determines whether the idle/busy information for the subscriber 11 1  stored in the memory part M4 is idle or busy. When the idle/memory information represents idle, the switching center 30 refers to the idle/busy information for the terminal 12 2  stored in the memory part M3. When this idle/busy information represents idle, the switching center 30 reads out the terminal number of a terminating terminal of a terminating subscriber stored in the terminating terminal memory part M2 and performs an outgoing call connection process. At this point, the switching center 30 also sets the idle/busy information for the subscriber 11 1  and the terminal 12 2  to busy state. When the subscriber 11 1  makes a call, while the terminating terminal 12 1  is performing an incoming call connection process for the subscriber 11 1 , since the idle/busy information for the subscriber 11 1  has been set to the busy state, even if the terminal 12 2  is idle, the switching center 30 does not perform an outgoing call connection process for the subscriber 11 1  at the terminal 12 2 .

This application is a divisional of U.S. patent application Ser. No.08/132,355, filed Oct. 6, 1996 (now abandoned).

BACKGROUND OF THE INVENTION

The present invention relates to a connection control method for use ina personal communication system for allowing each subscriber thereof tomake a call at any terminal to any designated terminal so as to provideadvanced services.

FIG. 1 is a block diagram showing the construction of a conventionalcommunication system. In a personal communication system, subscribers11₁, 11₂, 11₃, and so forth are designated by unique personal numbers(which are also denoted by 11₁, 11₂, 11₃, and so forth). Each subscribercan make a call using any terminal 12₁, 12₂, 12₃, and so forth (theterminal numbers thereof are also denoted by 12₁, 12₂, 12₃, and soforth). When a subscriber registers a desired terminal as a terminatingterminal to a switching center, he can receive incoming calls at theregistered terminal. In an example shown in FIG. 1, the terminals 12₁ to12₄ are accommodated in a switching center 30₁. In the figure, aterminal 12₅ is accommodated in a switching center 30₂ which isconnected to the switching center 30₁. The switching center 30₁comprises a terminating terminal memory part M2 and a terminal idle/busymemory part M3. The terminating terminal memory part M2 storesterminating terminal numbers corresponding to personal numbers of thesubscribers. The terminating terminal numbers are designated asterminating addresses by the subscribers. The terminal idle/busy memorypart M3 stores idle/busy information which represents the idle state orbusy state of each terminal depending on whether or not it iscommunicating (namely, performing an incoming/outgoing call connectionprocess). When the connection process is started, the busy state isregistered. On the other hand, when the communication session iscompleted, the idle state is registered.

Each subscriber can receive an incoming call at his registered terminal.On the other hand, each subscriber can make a call at any terminalregardless of whether it is his registered terminal. Unless otherwisespecified, each subscriber does not have a so-called call waitingservice where he can make a call at a terminal which is busy. In thisexample, terminating terminals of the subscribers 11₁, 11₂, 11₃, and soforth are denoted by 12₁, 12₂, 12₃, and so forth, respectively.

In a personal communication, when a subscriber makes a call, he inputsinto a terminal both his personal number and a terminating personalnumber or a terminating terminal number. Thus, an outgoing callconnection request takes place. The terminal sends this request to theswitching center connected thereto. The switching center interrogates aservice class of the subscriber corresponding to the receivedoriginating personal number from a subscriber service memory part M1.(The term "interrogate" means, throughout this specification, "retrieveand read out".) Thereafter, the switching center starts an outgoing callconnection process corresponding to the service class. For example, whenthe subscriber 11₁ makes a call at the terminal 12₂, the switchingcenter 30₁ refers to the idle/busy information for the terminal 12₂stored in the terminal idle/busy memory part M3. When the idle/busyinformation represents an idle state, the switching center 30₁ performsthe outgoing call connection process. Since the terminal 12₂ is aterminating terminal of the subscriber 11₂, if the switching center 30₁is performing a terminating call process to the subscriber 11₂ andtherefore his idle/busy state is busy when the subscriber 11₁ makes acall at the terminal 12₂, the switching center 30₁ does not perform theoriginating process for the subscriber 11₁.

When a call is terminated to the subscriber 11₁, the switching center30₁ refers to the idle/busy information for the terminal 12₁ stored inthe terminal idle/busy memory part M3 corresponding to the terminalnumber of the terminating terminal 12₁ of the subscriber 11₁ stored inthe terminating terminal memory part M2. When the idle/busy informationrepresents an idle state, the switching center 30₁ causes the callconnection control part 31 to connect the call to the terminal 12₁. Atthis point, if the subscriber 11₂ is communicating at the terminal 12₁,since the idle/busy information for the terminating terminal 12₁ of thesubscriber 11₁ represents a busy state, the switching center 30₁ doesnot perform the outgoing call connection process.

Since each subscriber cannot make calls, simultaneously, at a pluralityof terminals disposed at different locations, a service whichsimultaneously processes a plurality of communication requests for onesubscriber should be normally restricted. In the prior art, theswitching center only stores the idle/busy information for terminals.Thus, while the subscriber 11₁ is communicating at the terminal 12₂, ifthere is an incoming call to the subscriber 11₁, the switching center30₁ connects the incoming call to the registered terminal 12₁ of thesubscriber 11₁ when the terminal 12₁ is idle. Thus, the condition thatthe same subscriber is communicating at a plurality of terminals,simultaneously, is caused, which gives rise to a problem of providingdouble calls to the same contracted personal number.

Now assume that the subscribers 11₁, 11₂, etc. have a call waitingservice. In this condition, if there is a new incoming call to asubscriber who is already communicating (as a first communication), thesubscriber can receive the second communication while suspending thefirst communication. For example, when the subscriber 11₃ inputs thepersonal number of the subscriber 11₁ at the terminal 12₃, an outgoingcall connection request takes place. At this point, the switching center30₁ refers to the terminal idle/busy memory part M3 corresponding to theterminal number 12₁ of the terminating terminal 12₁ registered by thesubscriber 11₁ and stored in the terminating terminal memory part M2. Ifthe terminal 12₁ is idle, the switching center 30₁ causes the callconnection control part 31 to connect the incoming call to the terminal12₁. When the subscriber 11₁ replies to the incoming call at theterminal 12₁, the first communication is established.

Next, during the first communication, when a subscriber 11₄ inputs thepersonal number of the subscriber 11₁ at a terminal 12₄, a connectionrequest takes place. At this point, the switching center 30₁interrogates the terminal number 12₁ of the terminating terminal 12₁registered by the subscriber 11₁ and stored in the terminating terminalmemory part M2 and causes the call connection control part 31 to connectthe incoming call to the terminal 12₁. By suspending the firstcommunication at the terminal 12₁, the subscriber 11₁ can receive thesecond communication which is the incoming call from the subscriber 11₄.In addition, the subscriber 11₁ can suspend the second communication soas to restore the first communication.

In the above-described prior art, let it be supposed that the subscriber11₁ dialed the personal number of a subscriber 11₃ at a terminal 12₂other than his terminating terminal 12₁ which has been in a firstcommunication with the subscriber 11₃. At this point, if the subscriber11₄ originates a call for communication with the subscriber 11₁ at theterminal 12₄, the call to the subscriber 11₃ would be connected to theterminating terminal 12₁ as explained previously. Thus, the call is notreceived by the subscriber 11₁ who is communicating at the terminal 12₂.In other words, while a subscriber is communicating at a terminal otherthan his terminating terminal, he cannot have call waiting service. Inaddition, since the subscriber is communicating at a terminal other thanhis terminating terminal, the switching center eventually connects anincoming call to his registered terminal where he is absent.

In an integrated services digital network (ISDN) system, which is notnecessarily a personal communication system, each terminating terminalhas a display 12D as shown in FIG. 1. With the display 12D, a callingline identification service which displays the terminal number of anoriginating terminal is performed. In this system, each switching center30 shown in FIG. 1 comprises, as shown in FIG. 2, a call connectioncontrol part 31, a terminal number sending/receiving part 34, a terminalnumber transmitting part 35, and a personal number receiving part 36.The call connection control part 31 controls line connections betweenthe switching center and terminals or line connection with anotherswitching center. The terminal number sending/receiving part 34 sendsand receives terminal numbers to and from terminal 12₁. The terminalnumber transmitting part 35 sends and receives a terminal number to andfrom another switching center. The personal number receiving part 36receives personal numbers from terminals 12_(j).

When an originating subscriber 11₁ makes a call at a terminal 12₁, heinputs both his personal number and the terminal number of a terminatingterminal (for example, the terminal number of a terminal 12₅ as in FIG.1). At this point, the originating terminal 12₁ sends a SETUP message tothe switching center 30₁. The SETUP message serves to initiate the calland contains the terminal number of the terminating terminal, thepersonal number of the originating subscriber 11₁, and the terminalnumber of the originating terminal 12₁. Thus, the personal numberreceiving part 36 and the terminal number sending/receiving part 34 ofthe switching center 30₁ receive the terminal number of the terminatingterminal, the personal number of the originating subscriber 11₁, and theterminal number of the originating terminal 12₁. Thereafter, theswitching center 30₁ analyzes the terminal number of the terminatingterminal. If the terminal number of the terminating terminal is notaccommodated in the switching center 30₁, the terminal numbertransmitting part 35 of the switching center 30₁ transmits an IAMmessage to a switching center 30₂ which accommodates the terminatingterminal. The IAM message contains the terminal number of theoriginating terminal 12₁, and the terminal number of the terminatingterminal.

The switching center 30₂ sends a SETUP message to the terminatingterminal 12₅. The SETUP message serves to call the terminatingsubscriber 11₅ and contains the terminal number of the originatingterminal 12₁, and the terminal number of the terminating terminal. Theterminating terminal 12₅ displays the terminal number 12₁ of theoriginating terminal 12₁ on the display 12D. Thus, the terminatingsubscriber 11₅ can guess from the originating terminal number 12₁ on thedisplay 12D who the originating subscriber 11₁ could be and whichcompany or location the terminated call could be originated from.

When a call is sent from a telephone with a representative telephonenumber of a company or the like, it is impossible for a terminatingsubscriber to know by whom of the company the call is sent. When a callis sent from a mobile telephone (such as a car telephone or a portablecellular phone), if the mobile telephone is shared by several people, itis impossible for a terminating subscriber to know by whom the call issent. In the personal communication (personal number communication)system, each subscriber is given a unique personal number and anyterminal can be registered as his terminating terminal. Even if thecalling line identification service of the ISDN system is introduced tothe personal communication system, the terminating subscriber cannotknow the originating subscriber from the originating terminal numbersince each terminal can be used by any subscriber. Thus, even with theterminal number of an originating terminal displayed on the terminatingterminal, the terminating subscriber cannot estimate the identify of theoriginating subscriber. In other words, although each subscriber isgiven a unique personal number, it cannot be effectively used.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a connection controlmethod for personal communications which solves the aforementionedproblems.

In other words, a first object of the present invention is to provide aconnection control method for a personal communication for preventing anincoming call from being connected to a subscriber while he iscommunicating at a terminal.

A second object of the present invention is to provide a connectioncontrol method for personal communications that allows a subscriber toreceive an incoming call destined thereto while he is communicating at aterminal other than his registered terminal.

A third object of the present invention is to provide a connectioncontrol method for personal communications that allows a terminatingsubscriber to know a personal number of an originating subscriber.

According to a first aspect of the present invention, a subscriberidle/busy memory means is provided to store idle/busy information whichrepresents idle or busy state depending on whether or not a subscriberis communicating (namely, he is making a call or receiving a call). Whenthe subscriber makes a call or receives a call, the switching centerrefers to the idle/busy information for the subscriber from thesubscriber idle/busy memory means. When the idle/busy informationrepresents the idle state, the switching center refers to idle/busyinformation for the originating terminal or terminating terminal. Whenthe idle/busy information represents the idle state, the switchingcenter connects the call to the subscriber.

According to a second aspect of the present invention, while asubscriber is communicating, the switching center causes a communicatingterminal memory means to store the personal number of the subscriber andthe terminal number of a terminal at which the subscriber iscommunicating. When a second request for a call to the subscriber takesplace while the subscriber is already communicating, the switchingcenter connects the call to the communicating terminal corresponding tothe communicating terminal number interrogated from the communicatingterminal memory means.

According to a third aspect of the present invention, each switchingcenter is provided with a personal number transmitting means. Thepersonal number transmitting means sends and receives the personalnumber of each originating subscriber between each switching center soas to inform each terminating subscriber of the personal number of theoriginating subscriber. When a subscriber makes a call with his personalnumber, the originating terminal sends the personal number to theswitching center. The switching center causes the personal numbertransmitting means to transmit the personal number of the originatingsubscriber received from the originating terminal to the terminatingswitching center. The terminating switching center informs theterminating terminal of the personal number of the originatingsubscriber.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a conventional communication system;

FIG. 2 is a block diagram showing the construction of a switching centerwhich performs a calling line identification service of the system shownin FIG. 1;

FIG. 3 is a block diagram showing an example of a personal communicationsystem according to the present invention;

FIG. 4 is a flow chart showing an outgoing call connection processsequence performed by the system shown in FIG. 3;

FIG. 5 is a flow chart showing an incoming call connection processsequence performed by the system shown in FIG. 3;

FIG. 6 is a block diagram showing the construction of a personalcommunication system which performs a call waiting service;

FIG. 7 is a flow chart showing a connection process sequence of the callwaiting service;

FIG. 8 is a flow chart showing a modification of the embodiment shown inFIG. 7;

FIG. 9 is a block diagram showing the construction of a switching centerwhich performs the calling line identification service;

FIG. 10 is a flow chart showing a connection process sequence of thecalling line identification service; and

FIG. 11 is a block diagram showing a personal communication network foruse in a mobile communication system according to the connecting methodof the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 3 shows an example of a personal communication system according tothe present invention. For the sake of simplicity, portionscorresponding to FIG. 1 are denoted by the same reference numerals.FIGS. 4 and 5 show examples of communication connection controllingsequences for an outgoing call and an incoming call, respectively,according to the present invention. According to the present invention,switching centers 30₁, 30₂, and so forth each comprise a subscriberservice memory part M1, a terminating terminal memory part M2, aterminal idle/busy memory part M3, and a subscriber idle/busy memorypart M4. The subscriber idle/busy memory part M4 stores idle/busyinformation corresponding to the personal number of each subscriber.Whenever a communication connection process is started, thecorresponding terminal idle/busy information and the correspondingsubscriber idle/busy information stored in the idle/busy memory parts M3and M4 are set to busy state. In contrast, whenever the communication isfinished, they are set to idle state. In FIG. 3, the same portions asthose in FIG. 1 have the same functions.

In the personal communication, when a subscriber issues an outgoing callconnection request, he dials his personal number and the personal numberof a terminating subscriber so as to send them to a switching center. Atthis point, the terminal being used may automatically send its terminalnumber along with the originating personal number and the terminatingpersonal number to the switching center as with a mobile station in amobile communication system. Alternatively, the switching center mayinterrogate the terminal number from the line on which an outgoing callconnection request takes place. In any case, when the switching centerreceives the outgoing call connection request, it can know from whichterminal the outgoing call connection request is sent. Thus, theswitching center can know the terminal number of the originatingterminal. When a subscriber 11₁ makes a call at a terminal 12₂, he dialsboth his personal number 11₁ and the personal number of a terminatingsubscriber (for example, 11₃) so as to send an outgoing call connectionrequest to the switching center 30₁. When the switching center 30₁receives the outgoing call connection request, it interrogates a serviceclass corresponding to the personal number of the originating subscriberfrom the subscriber service memory part M1. With the service class, theswitching center 30₁ starts an outgoing call connection process as shownin FIG. 4. The outgoing call connection process shown in FIG. 4 is basedon a service class of a personal communication which does not include acall waiting service and a calling line identification service.

At step S1, the switching center 30₁ refers to the idle/busy informationfor the subscriber 11₁ stored in the subscriber idle/busy memory partM4. At step S2, the switching center 30₁ determines whether or not theidle/busy information represents idle state. When the determined resultat Step S2 is YES (namely, idle), the flow advances to step S3. At stepS3, the switching center 30₁ refers to the idle/busy information for aterminal 12₂ stored in the terminal idle/busy memory part M3. At stepS4, the switching center 30₁ determines whether or not the idle/busyinformation represents idle state. When the determined result at step S4is YES (idle), the flow advances to step S5. At step S5, the switchingcenter 30₁ interrogates a terminating terminal number 12₃ of aterminating subscriber 11₃ from the terminating terminal memory part M2as in FIG. 1. In addition, the switching center 30₁ performs an outgoingcall connection process for the terminal 12₃ and sets the idle/busyinformation for the subscriber 11₁ and the terminal 12₂ stored in thememory parts M4 and M3 to busy state. If the subscriber 11₁ makes acall, while the terminal 12₁ is receiving a call to him, the switchingcenter 30₁ determines that the idle/busy information for the subscriber11₁ is busy state at step S2. Thus, even if the terminal 12₂ is idle,the switching center 30₁ cancels the connection process against theoutgoing call connection request from the subscriber 11₁ at the terminal12₂ (at step S6). In addition, even if the switching center 30₁ hasdetermined that the subscriber 11₁ is idle at step S2, when it hasdetermined that the terminal 12₂ is busy at step S4, it cancels theoutgoing call connection process (at step S6).

When a call is terminated to the subscriber 11₁, as shown in FIG. 5, theswitching center 30₁ refers to the idle/busy information for thesubscriber 11₁ stored in the subscriber idle/busy memory part M4 at stepS1. At step S2, the switching center 30₁ determines whether or not theidle/busy information is idle. When the determined result at step S2 isYES (namely, idle), the flow advances to step S3. At step S3, theswitching center 30₁ interrogates the terminal number of the terminatingterminal 12₁ of the subscriber 11₁ stored in the terminating terminalmemory part M2. At step S4, the switching center 30₁ refers to theidle/busy information for the terminal 12₁ stored in the terminalidle/busy memory part M3 at step S4. Thereafter, the flow advances tostep S5. At step S5, the switching center 30₁ determines whether or notthe terminal 12₁ is idle. When the determined result at step S5 is YES(namely, idle), the flow advances to Step S6. At step S6, the callconnection control part 31 connects the call to the terminal 12₁.However, when the call is terminated to the subscriber 11₁ while he iscommunicating at for example the terminal 12₂, the idle/busy informationfor the subscriber 11₁ represents busy state, and therefore the flowadvances from step S2 to step S7. At step S7, the switching center 30₁cancels the outgoing call connection process for the subscriber 11₁. Inaddition, when the determined result at step S5 is NO (namely, busy),the switching center 30₁ cancels the incoming call connection processfor the subscriber 11₁ (at step S7).

FIG. 6 shows an example of the construction of a switching center 30 ofa personal communication system which can provide a call waitingservice. FIG. 7 shows an example of a connection process sequence of thecall waiting service. In this embodiment, a switching center 30comprises a subscriber service memory part M1, a terminating terminalmemory part M2, a terminal idle/busy memory part M3, a subscriberidle/busy memory part M4, and a communicating terminal memory part M5.The memory parts M1 to M4 of FIG. 6 are the same as those of FIG. 3. Thecommunicating terminal memory part M5 stores the terminal number of eachterminal at which each subscriber is communicating. In FIG. 6, the samereference numerals as FIG. 3 have functions similar thereto.

First, a subscriber 11₁ at a terminal 12₂ dials both his personal number11₁ and the personal number 11₃ of a terminating subscriber 11₃.According to the same process sequence as FIG. 4, when a firstcommunication is established between the subscribers 11₁ and 11₃, theswitching center 30 registers the terminal number 12₂ of the operatingterminal 12₂ corresponding to the personal number 11₁ of the subscriber11₁ stored in the communicating terminal memory part M5.

Next, while the subscriber 11₁ is communicating (as the firstcommunication), if another subscriber 11₄ issues a communication requestto the subscriber 11₁ from a terminal 12₄ at step S1 of FIG. 7, theswitching center 30 refers to the communicating terminal memory part M5at step S2 and interrogates the communicating terminal informationcorresponding to the subscriber 11₁. At step S3, the switching center 30determines whether or not the subscriber 11₁ is communicating. When thesubscriber 11₁ is communicating, the switching center 30 determines atwhich terminal the subscriber 11₁ is communicating. In this example,since the terminal number 12₁ of the terminal 12₁ at which thesubscriber 11₁ is communicating is stored as communicating terminalinformation in the communicating terminal memory part M5, the switchingcenter 30 causes the call connection control part 31 to connect awaiting call to the terminal 12₂ at step S4. Thus, the subscriber 11₁who is communicating in the first communication knows that there is anew incoming call to him. When the subscriber 11₁ issues an incomingcall switching connection request to the switching center 30, itperforms the incoming call switching connection process which switchesthe connection with the terminal 12₂ to the connection with the terminal12₄ at step S5. Thus, a second communication from the subscriber 11₄ tothe subscriber 11₁ is established. When the subscriber 11₁ issues theincoming call switching connection request to the switching center 30,it restores the first communication for him.

When the communicating terminal number of the subscriber 11₁ has notbeen stored in the communicating terminal memory part M5 at step S3(namely, the determined result at step S3 is NO), the switching center30 refers to the terminating terminal memory part M2 at step S6 andinterrogates the terminal number 12₁ of the terminating terminal 121 ofthe subscriber 11₁. At step S7, the switching center 30 performs theincoming call connection process for the terminal 12₁ at step S7. Inaddition, the switching center 30 registers the communicating terminalnumber 12₁ corresponding to the subscriber 11₁ of the communicatingterminal memory part M5.

After step S5, even if the subscriber 11₁ completes either the firstcommunication or the second communication, the terminal number 12₂ ofthe communicating terminal 12₂ stored for the subscriber 11₁ in thecommunicating terminal memory part M5 is not erased. When bothcommunications are finished, the communicating terminal number 12₂ iserased from the communicating terminal memory part M5.

FIG. 8 shows a modification of the above-described embodiment of FIG. 7in which the process sequence of the call waiting service is modifiedsuch that, as with the embodiment shown in FIG. 5, the switching centerrefers to the subscriber idle/busy memory part M4 and determines whetheror not a relevant terminating subscriber is communicating.

As with the above-described embodiments, assume that a subscriber 11₁who uses a terminal 12₂ is communicating with a subscriber 11₃ who usesa terminal 12₃ (a first communication). In this situation, when asubscriber 11₄ issues an incoming call connection request to thesubscriber 11₁ at step S1, the switching center 30 interrogates theidle/busy information for the terminating subscriber 11₁ from thesubscriber idle/busy information memory part M4 at step S2. At step S3,the switching center 30 determines whether or not the terminatingsubscriber 11₁ is idle. In this example, since the subscriber 11₁ iscommunicating with the subscriber 11₃, the idle/busy information for thesubscriber 11₁ is busy. Thus, the flow advances to step S4. At step S4,the switching center 30 refers to the communicating terminal memory partM5 and interrogates the communicating terminal 12₂ of the subscriber11₁. Thereafter, at step S5, when the switching center 30 receives anincoming call switching connection request from the subscriber 11₁, itperforms, at step S6, an incoming call switching connection processwhich switches the connection of the terminal 12₂ to connection with theterminal 12₄, thus establishing a second communication. When thesubscriber 11₁ does not have the first communication, since theswitching center 30 has determined that the subscriber idle/busyinformation is idle at step S3, it interrogates the terminating terminalnumber 12₁ of the terminating subscriber 11₁ at step S7, and then atstep S8, the switching center 30 performs the connection process for theterminating terminal 12₁ and stores the communicating terminal number12₁ corresponding to the subscriber 11₁ in the communicating terminalnumber memory part M5 in the same manner as described at steps S6 and S7of FIG. 7.

FIG. 9 shows the construction of a switching center 30 which provides aservice of identifying the personal number of an originating subscriberalong with the originating terminal number identification service of theembodiment shown in FIG. 3. In FIG. 9, the switching center 30 comprisesa call connection control part 31, a subscriber service memory part M1,a terminating terminal memory part M2, a terminal idle/busy informationmemory part M3, a terminal number sending/receiving part 34, a terminalnumber transmitting part 35, a personal number sending/receiving part37, and a personal number transmitting part 38. The call connectioncontrol part 31, the subscriber service memory part M1, the terminatingterminal memory part M2, the terminal idle/busy information memory partM3, and the terminal number sending/receiving part 34 of FIG. 9 are thesame as those of FIG. 3. The terminal number sending/receiving part 34and the terminal number transmitting part 35 of FIG. 9 are the same asthose of FIG. 2. The personal number sending/receiving part 37 sends andreceives a personal number to and from the terminal 12_(j). The personalnumber transmitting part 38 sends and receives a personal number betweenswitching centers.

FIG. 10 shows a connection process sequence of the calling lineidentification service performed by the switching center 30 shown inFIG. 9. In the system shown in FIG. 3, when an originating subscriber11₁ makes a call to a subscriber 11₅, he dials both his personal number11₁ and the personal number 11₅ of a terminating subscriber 11₅ at aterminal 12₁ (at step S1). At this point, the terminal 12₁ sends a SETUPmessage to the switching center 30₁ (at step S2). The SETUP messageserves to initiate a call and contains the terminating personal number11₅, the personal number 11₁ of the originating subscriber 11₁, and theterminal number 12₁ of the originating terminal 12₁.

The switching center 30₁ receives the terminating personal number 11₅,the personal number 11₁ of the originating subscriber 11₁, and theterminal number 12₁ of the originating terminal 12₁. The switchingcenter 30₁ determines whether or not the terminating personal number isaccommodated therein (at step S3). When the terminating personal numberis not accommodated, the switching center 30₁ sends an IAM (initialaddress message) message to a terminating switching center 30₂ whichaccommodates the terminating personal number (at step S4). The IAMmessage serves to transmit the outgoing call to the terminatingswitching center 30₂ and contains the terminal number 12₁ of theoriginating terminal 12₁, the terminating personal number 11₅, and thepersonal number 11₁ of the originating subscriber 11₁.

The terminating switching center 30₂ interrogates the terminal number12₅ of the terminating terminal corresponding to the terminatingsubscriber 11₅ from the terminating terminal memory part M2. Thereafter,with the terminal number 12₅, the switching center 30₂ interrogates theidle/busy information from the terminal idle/busy memory part M3. Whenthe terminal 12₅ is idle, the switching center 30₂ sends a SETUP messageto the terminating terminal 12₅ (at step S5). The SETUP message servesto call the terminal 12₅ and contains the terminal number 12₁ of theterminating terminal 12₁ and the personal number 11₁ of the originatingsubscriber 11₁.

The terminating terminal 12₅ displays the terminal number 12₁ of theoriginating terminal 12₁ and the personal number 11₁ of the originatingsubscriber 11₁ (at step S6). Thus, the terminating subscriber 11₅ canknow the terminal number 12₁ of the originating terminal 12₁ and thepersonal number 11₁ of the originating subscriber 11₁. In this case, theterminating terminal 12₅ may display only the personal number 11₁ of theoriginating subscriber 11₁. Thus, the terminating subscriber 11₅ canguess who is the originating subscriber. In other words, when theoriginating terminal 12₁ is installed in an office of a company and theterminal 12₁ is shared by a plurality of subscribers, since the personalnumber of a subscriber which uses the terminal 12₁ is displayed on thedisplay 12D, the terminating subscriber can identify the originatingsubscriber.

In the above example, it was assumed that the terminal registered by theterminating subscriber 11₅ as a terminating terminal was notaccommodated in the switching center 30₁. However, at steps S1 and S2,if the terminating subscriber is for example 11₃, the switching center30₁ determines that the terminating terminal 12₃ is accommodated thereinat step 3. Thus, the flow advances from step S3 to step S7 of FIG. 10.

At step S7, the terminating center 30₁ interrogates the terminal number12₃ of the terminating terminal corresponding to the terminatingsubscriber 11₃ from the terminating terminal memory part M2 thereof.Thereafter, with the terminal number 12₃, the switching center 30₁interrogates the idle/busy information from the terminal idle/busymemory part M3. When the terminal 12₃ is idle, the switching center 30₁sends a SETUP message to the terminating terminal 12₃. The SETUP messageserves to call the terminal 12₃ and contains the terminal number of theoriginating terminal 12₁ and the personal number 11₁ of the originatingsubscriber 11₁.

At step S8, the terminating terminal 12₃ displays the terminal number12₁ of the originating terminal 12₁ and the personal number 11₁ of theoriginating subscriber 11₁ on the display 12D. Thus, the terminatingsubscriber 11₃ can know these numbers through the display 12D.

The above-described embodiments may be applied for personalcommunications in a mobile communication network as well as for those inthe conventional telephone network. FIG. 11 shows an example of themobile communication system according to the present invention. Toeffect mobile communication, car telephones, portable cellular phones,and so forth may be used. In this example, mobile communication usingcar telephones will be described. In FIG. 11, reference numerals 12M₁,12M₂, and so forth function as terminals for use in the above-describedpersonal communications. The mobile stations 12M₁, 12M₂, and so forthcan communicate with their nearest base stations 40₁, 40₂, and so forththrough radio channels. The base stations 40₁, 40₂, and so forth arelinked to switching centers 30₁, 30₂, and so forth. The presentlocations of the mobile stations 12M₁, 12M₂, and so forth are alwayssupervised by the switching centers 30₁, 30₂, . . . and stored inlocation memories (not shown) thereof. Thus, each subscriber can make acall from his mobile station as an originating terminal to anyterminating terminal which may be a mobile station or a fixed terminal(not shown). In addition, any mobile station as a terminating terminalcan receive an incoming call from any terminal. When a subscriber uses aparticular mobile station as a personal communication terminal, providedthat the station number of the mobile station as a terminating terminalis registered to the switching center, he can have various classes ofpersonal communication services according to the connection processsequence of the present invention.

As described above, according to the first aspect of the presentinvention, the switching center refers to the idle/busy information forthe subscriber stored in the subscriber idle/busy memory part M4. Whilethe subscriber is communicating at a particular terminal and isperforming an incoming/outgoing call connection process, the switchingcenter can restrict the incoming/outgoing call connection process forthis subscriber against another terminal.

According to the second aspect of the present invention, the switchingcenter stores the terminal number of a communicating terminal of eachsubscriber. With the communicating terminal number, the switching centerperforms a call waiting process for the subscriber. Thus, even if asecond communication request takes place for a subscriber who iscommunicating at a terminal other than his terminating terminal, theswitching center can perform an incoming call connection process for theterminal at which the subscriber is actually communicating rather thanperforming a useless incoming call connection process for a terminalthat the subscriber is not using at the time. Thus, the subscriber cansecurely have a call waiting service at any terminal.

In addition, according to the third aspect of the present invention,when an originating subscriber makes a call with his personal number, anoriginating switching center transmits the call to a terminatingswitching center along with the personal number of the originatingsubscriber. The terminating switching center transmits the personalnumber of the originating subscriber to a terminating terminal. Thus,the terminating terminal can display the personal number of theoriginating subscriber.

In the above-described embodiments, the switching center 30 comprisesthe terminating terminal memory part M2, the terminal idle/busy memorypart M3, the subscriber idle/busy memory part M4, and the communicatingterminal memory part M5. However, these memory parts may be replaced bya database or the like. When the switching center interrogates requireddata from the database, the same effect may be accomplished. Althoughthe terminating terminal memory part M2 and the subscriber idle/busymemory part M4 were independently provided according to the embodimentshown in FIG. 3, both the terminating terminal number and the idle/busyinformation thereof may be registered in one memory part using thepersonal number of each subscriber as a common address therefor. In thisconstruction, when the personal number of each subscriber isinterrogated from the memory part, both the idle/busy information andthe terminating terminal number thereof may be obtained. Likewise, inthe embodiment shown in FIG. 6, the terminating terminal number, theidle/busy information, and the communicating terminal number can beregistered at the same address corresponding to the personal number ofeach subscriber in one memory part instead of the individual memoryparts M2, M4, and M5. In addition, this construction may apply to theembodiment shown in FIG. 9.

What is claimed is:
 1. A call connection method in a personalcommunication system, said personal communication system including aplurality of switching centers, each of said plurality of switchingcenters comprising: a plurality of terminals; a plurality of subscriberseach having a personal number unique thereto; terminal numbersending/receiving means for sending and receiving terminal numbers toand from said plurality of terminals; personal number sending/receivingmeans for sending and receiving personal numbers to and from saidplurality of terminals; terminal number transmitting means for sendingand receiving to and from another switching center the terminal numberof an originating terminal used by an originating subscriber to issue anoutgoing call and the terminal number of a terminating terminal;personal number transmitting means for sending and receiving a personalnumber of an originating subscriber to and from another switchingcenter; and terminal idle/busy memory means for storing terminalidle/busy information in correspondence with the terminal number of eachterminal,said call connection method comprising, when any one of thesubscribers accommodated within one switching center performs a personalcommunication with any one of the subscribers accommodated withinanother switching center by using any one of the terminals accommodatedwithin said one switching center, the steps of:(A) performing anoriginating process by which an originating subscriber within said oneswitching center inputs the personal number of said originatingsubscriber and the terminal number of a terminating subscriber withinsaid another switching center by using any one of the terminals withinsaid one switching center as an originating terminal; (B) at theoriginating terminal, sending the personal number of the originatingsubscriber and the terminal number of the terminating subscribertogether with the terminal number of the originating terminal from saidoriginating terminal to said one switching center; (C) at said oneswitching center, receiving the personal number of the originatingsubscriber by use of the personal number sending/receiving means withinsaid one switching center, and concurrently receiving both the terminalnumbers of the originating terminal and the terminating subscriber byuse of the terminal number sending/receiving means within said oneswitching center; (D) at said one switching center, transmitting thepersonal number of the originating subscriber from said one switchingcenter to said another switching center by use of the personal numbertransmitting means within said one switching center, and concurrentlytransmitting both the terminal numbers of the originating terminal andthe terminating subscriber from said one switching center to saidanother switching center by use of the terminal number transmittingmeans within said one switching center; and (E) at said anotherswitching center, receiving the personal number of the originatingsubscriber by use of the personal number transmitting means within saidanother switching center, and concurrently receiving both the terminalnumbers of the originating terminal and the terminating subscriber byuse of the terminal number transmitting means within said anotherswitching center, and when the terminating terminal corresponding to thereceived terminal number of the terminating subscriber is not busy as aresult of retrieval of the terminal idle/busy memory means within saidanother switching center, calling the terminating terminal by use of theterminal number sending/receiving means within said another switchingcenter and sending the received personal number of the originatingsubscriber and the received terminal number of the originating terminalby use of the personal number sending/receiving means and the terminalnumber sending/receiving means within said another switching center,respectively.
 2. The method as set forth in claim 1, further includingthe step of:(F) at the called terminating terminal, displaying both thepersonal number of the originating subscriber and the terminal number ofthe originating terminal on display means of said called terminatingterminal.
 3. A call connection method in a personal communicationsystem, said personal communication system including a plurality ofswitching centers, each of said plurality of switching centerscomprising: a plurality of terminals; a plurality of subscribers eachhaving a personal number unique thereto; terminal numbersending/receiving means for sending and receiving terminal numbers toand from said plurality of terminals; personal number sending/receivingmeans for sending and receiving personal numbers to and from saidplurality of terminals; terminal number transmitting means for sendingand receiving to and from another switching center the terminal numberof an originating terminal used by an originating subscriber to issue anoutgoing call and the terminal number of a terminating terminal;personal number transmitting means for sending and receiving a personalnumber of an originating subscriber to and from another switchingcenter; and terminal idle/busy memory means for storing terminalidle/busy information in correspondence with the terminal number of eachterminal,said call connection method comprising, when any one of thesubscribers accommodated within one switching center performs a personalcommunication with any one of the subscribers accommodated withinanother switching center by using any one of the terminals accommodatedwithin said one switching center, the steps of:(A) performing anoriginating process by which an originating subscriber within said oneswitching center inputs the personal number of said originatingsubscriber and the terminal number of a terminating subscriber withinsaid another switching center by using any one of the terminals withinsaid one switching center as an originating terminal; (B) at theoriginating terminal, sending the personal number of the originatingsubscriber and the terminal number of the terminating subscriber fromsaid originating terminal to said one switching center; (C) at said oneswitching center, receiving the personal number of the originatingsubscriber from the originating terminal by use of the personal numbersending/receiving means within said one switching center, andconcurrently receiving the terminal number of the terminating subscriberfrom the originating terminal by use of the terminal numbersending/receiving means within said one switching center, and retrievingthe terminal number of the originating terminal; (D) at said oneswitching center, transmitting the personal number of the originatingsubscriber from said one switching center to said another switchingcenter by use of the personal number transmitting means within said oneswitching center, and concurrently transmitting both the terminalnumbers of the originating terminal and of the terminating subscriberfrom said one switching center to said another switching center by useof the terminal number transmitting means within said one switchingcenter; and (E) at said another switching center, receiving the personalnumber of the originating subscriber by use of the personal numbertransmitting means within said another switching center, andconcurrently receiving both the terminal numbers of the originatingterminal and of the terminating subscriber by use of the terminal numbertransmitting means within said another switching center, and when theterminating terminal corresponding to the received terminal number ofthe terminating subscriber is not busy as a result of retrieval of theterminal idle/busy memory means within said another switching center,calling the terminating terminal by use of the terminal numbersending/receiving means within said another switching center and sendingthe received personal number of the originating subscriber and thereceived terminal number of the originating terminal by use of thepersonal number sending/receiving means and the terminal numbersending/receiving means within said another switching center,respectively.
 4. The method as set forth in claim 3, further includingthe step of:(F) at the called terminating terminal, displaying both thepersonal number of the originating subscriber and the terminal number ofthe originating terminal on display means of said called terminatingterminal.
 5. A call connection method in a personal communicationsystem, said personal communication system including a plurality ofswitching centers, each of said plurality of switching centerscomprising: a plurality of terminals; a plurality of subscribers eachhaving a personal number unique thereto; terminal numbersending/receiving means for sending and receiving terminal numbers toand from said plurality of terminals; personal number sending/receivingmeans for sending and receiving personal numbers to and from saidplurality of terminals; terminal number transmitting means for sendingand receiving to and from another switching center the terminal numberof an originating terminal used by an originating subscriber to issue anoutgoing call and the terminal number of a terminating terminal;personal number transmitting means for sending and receiving a personalnumber of an originating subscriber to and from another switchingcenter; and terminal idle/busy memory means for storing terminalidle/busy information in correspondence with the terminal number of eachterminal,said call connection method comprising, when any one of thesubscribers accommodated within one switching center performs a personalcommunication with any one of the subscribers accommodated withinanother switching center by using any one of the terminals accommodatedwithin said one switching center, the steps of:(A) performing anoriginating process by which an originating subscriber within said oneswitching center inputs the personal number of said originatingsubscriber and both the terminal number and the personal number of aterminating subscriber within said another switching center by using anyone of the terminals within said one switching center as an originatingterminal; (B) at the originating terminal, sending both the personalnumbers of the originating subscriber and of the terminating subscriberand concurrently sending the terminal number of the terminatingsubscriber together with the terminal number of the originating terminalfrom said originating terminal to said one switching center; (C) at saidone switching center, receiving both the personal numbers of theoriginating subscriber and of the terminating subscriber from theoriginating terminal by use of the personal number sending/receivingmeans within said one switching center, and concurrently receiving boththe terminal numbers of the originating terminal and of the terminatingsubscriber from the originating terminal by use of the terminal numbersending/receiving means within said one switching center; (D) at saidone switching center, transmitting the personal number of theoriginating subscriber from said one switching center to said anotherswitching center by use of the personal number transmitting means withinsaid one switching center, and concurrently transmitting both theterminal numbers of the originating terminal and of the terminatingsubscriber from said one switching center to said another switchingcenter by use of the terminal number transmitting means within said oneswitching center; and (E) at said another switching center, receivingthe personal number of the originating subscriber by use of the personalnumber transmitting means within said another switching center, andconcurrently receiving both the terminal numbers of the originatingterminal and of the terminating subscriber by use of the terminal numbertransmitting means within said another switching center, and when theterminating terminal corresponding to the received terminal number ofthe terminating subscriber is not busy as a result of retrieval of theterminal idle/busy memory means within said another switching center,calling the terminating terminal by use of the terminal numbersending/receiving means within said another switching center and sendingthe received personal number of the originating subscriber and thereceived terminal number of the originating terminal by use of thepersonal number sending/receiving means and the terminal numbersending/receiving means within said another switching center,respectively.
 6. The method as set forth in claim 5, further includingthe step of:(F) at the called terminating terminal, displaying both thepersonal number of the originating subscriber and the terminal number ofthe originating terminal on display means of said called terminatingterminal.
 7. A call connection method in a personal communicationsystem, said personal communication system including a plurality ofswitching centers and a database which is accessed by each switchingcenter to read out required data thereof, each of said plurality ofswitching centers comprising: a plurality of terminals; a plurality ofsubscribers each having a personal number unique thereto; terminalnumber sending/receiving means for sending and receiving terminalnumbers to and from said plurality of terminals; personal numbersending/receiving means for sending and receiving personal numbers toand from said plurality of terminals; terminal number transmitting meansfor sending and receiving to and from another switching center theterminal number of an originating terminal used by an originatingsubscriber to issue an outgoing call and the terminal number of aterminating terminal; and personal number transmitting means for sendingand receiving a personal number of an originating subscriber to and fromanother switching center,said database comprising terminal idle/busymemory means for storing terminal idle/busy memory means for storingterminal idle/busy information in correspondence with the terminalnumber of each terminal within all the switching centers and terminatingterminal memory means for storing the terminal number of a terminatingterminal in correspondence with the personal number of each subscriberwithin all the switching centers, said terminal number of theterminating terminal having been registered by each subscriber as his orher terminating terminal to which an incoming call for him or her shouldbe connected, said call connection method comprising, when any one ofthe subscribers accommodated within one switching center performs apersonal communication with any one of the subscribers accommodatedwithin another switching center by using any one of the terminalsaccommodated within said one switching center, the steps of:(A)performing an originating process by which an originating subscriberwithin said one switching center inputs the personal number of saidoriginating subscriber and the personal number of a terminatingsubscriber within said another switching center by using any one of theterminals within said one switching center as an originating terminal;(B) at the originating terminal, sending both the personal numbers ofthe originating subscriber and of the terminating subscriber from saidoriginating terminal to said one switching center; (C) at said oneswitching center, receiving both the personal numbers of the originatingsubscriber and of the terminating subscriber from the originatingterminal by use of the personal number sending/receiving means withinsaid one switching center, and accessing the database using the receivedpersonal number of the terminating subscriber to read out the terminalnumber of the terminating terminal; (D) at said one switching center,transmitting the personal number of the originating subscriber from saidone switching center to said another switching center by use of thepersonal number transmitting means within said one switching center, andconcurrently transmitting both the terminal numbers of the originatingterminal and of the terminating subscriber from said one switchingcenter to said another switching center by use of the terminal numbertransmitting means within said one switching center; (E) at said anotherswitching center, receiving the personal number of the originatingsubscriber by use of the personal number transmitting means within saidanother switching center, and concurrently receiving both the terminalnumbers of the originating terminal and of the terminating subscriber byuse of the terminal number transmitting means within said anotherswitching center, and when the terminating terminal corresponding to thereceived terminal number of the terminating subscriber is not busy as aresult of access of the database, calling the terminating terminal byuse of the terminal number sending/receiving means within said anotherswitching center and sending the received personal number of theoriginating subscriber and the received terminal number of theoriginating terminal by use of the personal number sending/receivingmeans and the terminal number sending/receiving means within saidanother switching center, respectively.
 8. The method as set forth inclaim 7, further including the step of:(F) at the called terminatingterminal, displaying both the personal number of the originatingsubscriber and the terminal number of the originating terminal ondisplay means of said called terminating terminal.
 9. A call connectionmethod in a personal communication system, said personal communicationsystem including a plurality of switching centers and a database whichis accessed by each switching center to read out required data thereof,each of said plurality of switching centers comprising: a plurality ofterminals; a plurality of subscribers each having a personal numberunique thereto; terminal number sending/receiving means for sending andreceiving terminal numbers to and from said plurality of terminals;personal number sending/receiving means for sending and receivingpersonal numbers to and from said plurality of terminals; terminalnumber transmitting means for sending and receiving to and from anotherswitching center the terminal number of an originating terminal used byan originating subscriber to issue an outgoing call and the terminalnumber of a terminating terminal; and personal number transmitting meansfor sending and receiving a personal number of an originating subscriberto and from another switching center,said database comprising terminalidle/busy memory means for storing terminal idle/busy information incorrespondence with the terminal number of each terminal within all theswitching centers and terminating terminal memory means for storing theterminal number of a terminating terminal in correspondence with thepersonal number of each subscriber within all the switching centers,said terminal number of the terminating terminal having been registeredby each subscriber as his or her terminating terminal to which anincoming call for him or her should be connected, said call connectionmethod comprising, when any one of the subscribers accommodated withinone switching center performs a personal communication with any one ofthe subscribers accommodated within another switching center by usingany one of the terminals accommodated within said one switching center,the steps of:(A) performing an originating process by which anoriginating subscriber within said one switching center inputs thepersonal number of said originating subscriber and the terminal numberof a terminating subscriber within said another switching center byusing any one of the terminals within said one switching center as anoriginating terminal; (B) at the originating terminal, sending thepersonal number of the originating subscriber and the terminal number ofthe terminating subscriber form said originating terminal to said oneswitching center; (C) at said one switching center, receiving thepersonal number of the originating subscriber from the originatingterminal by use of the personal number sending/receiving means withinsaid one switching center, and concurrently receiving the terminalnumber of the terminating subscriber from the originating terminal byuse of the terminal number sending/receiving means within said oneswitching center, and retrieving the terminal number of the originatingterminal; (D) at said one switching center, transmitting the personalnumber of the originating subscriber from said one switching center tosaid another switching center by use of the personal number transmittingmeans within said one switching center, and concurrently transmittingboth the terminal numbers of the originating terminal and of theterminating subscriber from said one switching center to said anotherswitching center by use of the terminal number transmitting means withinsaid one switching center; (E) at said another switching center,receiving the personal number of the originating subscriber by use ofthe personal number transmitting means within said another switchingcenter, and concurrently receiving both the terminal numbers of theoriginating terminal and of the terminating subscriber by use of theterminal number transmitting means within said another switching center,and when the terminating terminal corresponding to the received terminalnumber of the terminating subscriber is not busy as a result of accessof the database, calling the terminating terminal by use of the terminalnumber sending/receiving means within said another switching center andsending the received personal number of the originating subscriber andthe received terminal number of the originating terminal by use of thepersonal number sending/receiving means and the terminal numbersending/receiving means within said another switching center,respectively.
 10. The method as set forth in claim 9, further includingthe step of:(F) at the called terminating terminal, displaying both thepersonal number of the originating subscriber and the terminal number ofthe originating terminal on display means of said called terminatingterminal.